add usb drive to .net standard (#1316)

SIL.Core.Desktop/UsbDrive/UsbDriveInfo.cs

@@ -1,13 +1,10 @@
-#if !NETSTANDARD
-// Copyright (c) 2009-2016 SIL International
+// Copyright (c) 2009-2016 SIL International
 // This software is licensed under the MIT License (http://opensource.org/licenses/MIT)
 
 using System;
 using System.Collections.Generic;
 using System.IO;
-using SIL.PlatformUtilities;
-using SIL.UsbDrive.Linux;
-using SIL.UsbDrive.Windows;
+using System.Linq;
 
 namespace SIL.UsbDrive
 {
@@ -21,6 +18,26 @@ public interface IUsbDriveInfo
 		ulong AvailableFreeSpace { get; }
 	}
 
+	internal class UsbDriveWrapper : IUsbDriveInfo
+	{
+		private DriveInfo _driveInfo;
+
+		public UsbDriveWrapper(DriveInfo driveInfo)
+		{
+			_driveInfo = driveInfo;
+		}
+
+		public ulong AvailableFreeSpace => (ulong)_driveInfo.AvailableFreeSpace;
+
+		public bool IsReady => _driveInfo.IsReady;
+
+		public DirectoryInfo RootDirectory => _driveInfo.RootDirectory;
+
+		public ulong TotalSize => (ulong) _driveInfo.TotalSize;
+
+		public string VolumeLabel => _driveInfo.VolumeLabel;
+	}
+
 	/// <summary>
 	/// This class allows tests to set up pretend usb drives, in order to test situations like
 	/// 1) no drives found
@@ -103,8 +120,12 @@ public abstract ulong TotalSize
 
 		public static List<IUsbDriveInfo> GetDrives()
 		{
-			if (Platform.IsWindows)
-				return UsbDriveInfoWindows.GetDrives();
+#if NETSTANDARD
+			return DriveInfo.GetDrives().Where(d => d.DriveType == DriveType.Removable)
+				.Select(d => new UsbDriveWrapper(d)).ToList<IUsbDriveInfo>();
+#else
+			if (PlatformUtilities.Platform.IsWindows)
+				return Windows.UsbDriveInfoWindows.GetDrives();
 
 			// Using SIL.UsbDrive on Linux/Mono results in NDesk spinning up a thread that
 			// continues until NDesk Bus is closed.  Failure to close the thread results in a
@@ -115,11 +136,11 @@ public static List<IUsbDriveInfo> GetDrives()
 			// Ubuntu 12.04 uses udisks. HAL use is deprecated.
 			// Ubuntu 14.04 can use udisks or udisks2.
 			// Ubuntu 16.04 uses udisks2.
-			return UsbDriveInfoUDisks2.IsUDisks2Available
-				? UsbDriveInfoUDisks2.GetDrives()
-				: UsbDriveInfoUDisks.GetDrives();
+			return Linux.UsbDriveInfoUDisks2.IsUDisks2Available
+				? Linux.UsbDriveInfoUDisks2.GetDrives()
+				: Linux.UsbDriveInfoUDisks.GetDrives();
+#endif
 		}
 	}
 
-}
-#endif
+}